STORY ARCHIVE

Astronauts need more than observatories to search deep space, they also use balloons the size of football fields. But, as Graham Phillips discovers in Alice Springs, even with an international crew of astrophysicists and engineers, launching a balloon loaded with expensive x-ray and gamma-ray telescopes is a risky job.

Space Balloons: Launching NASA balloon telescopes

TRANSCRIPT

NARRATIONOur universe is a relatively peaceful place, by and large. But there are spots where the environment is extraordinarily extreme, the regions near black holes. Here matter is thrust around with astonishing energy. People who study these violent neighbourhoods are high-energy astrophysicists.

Dr Graham PhillipsYou look at some of the most extreme and exciting objects in the universe.

Dr Jessica GaskinWhat’s exciting about it is that not only do you see some of the most highly energetic events that take place in our universe. You’re exploring a region of space that is still relatively unknown.

NARRATIONRelatively unknown, because our usual Earth-based telescopes are not that useful when it comes to black holes. It’s better to have a telescope above the Earth’s obscuring atmosphere that can see gamma rays and x-rays. This is an x-ray telescope. It will fly on a high altitude helium balloon.

Dr Graham PhillipsGee it’s a big instrument to be launching on a balloon. There must be a lot of helium you put in that balloon.

Dr Jessica GaskinAround 50 million cubic feet.

Dr Graham PhillipsReally!

NARRATIONUsing remote control, the telescope can be rotated to its target position, just like an Earth-based one.

Dr Jessica GaskinAt the top we have a rotation wheel and at the sides we have something that allows us to look at different elevations. And so the telescope can pivot in any direction we want it to go.

NARRATIONAnd, on another balloon, this gamma ray telescope will be launched.

Dr Graham PhillipsSo the main instrument’s in here?

Eric BellmYes, that’s correct. In there we have a gold box, which holds our germanium detectors and they’re cooled by liquid nitrogen to 77 Kelvin, so they have to be very cold to operate properly.

NARRATIONA few weeks earlier, the team successfully launched a telescope. Now they're keen to get these next two off the ground. But here’s the tough thing with balloon astronomy, to see if the weather’s right to launch you have to get up very early.

Dr Graham PhillipsWell it’s two o’clock in the morning here at Alice Springs airport. This is where the balloons will be launched from. I got up at 12:30 at night for this, don’t think I have ever done that before, but it’s should be a very exciting day.

NARRATIONEveryone gathers for the 2:30am weather report. But the news is not good.

Dr Graham PhillipsWe’ve got up for nothing this morning, I’ve got to come back again at 2am tomorrow morning and do it again, they call it groundhog day in the ballooning business.

NARRATIONWell, it does at least give us time to ponder the big questions the telescopes might answer. Eric hopes to see one of the brightest flashes in the cosmos. They’re called Gamma Ray Bursts and one of the sources of them is thought to be highly dense dead stars known as neutron stars. If two are orbiting each other they can spiral in and collide, causing an eruption of gamma rays. Or a gamma ray burst might come from a massive rotating exploding star.

Eric BellmIt can drive this jet out along the rotation axis, and matter collides within this jet and accelerates particles and produces a short burst of gamma rays anywhere from a second to a few hundred seconds, that, when it goes off, it's one of the brightest things in the universe.

NARRATIONThe astrophysicists are keen to study the heart of our galaxy.

Eric BellmAt the centre of our galaxy, there’s a fairly large cloud of positrons so that’s, it's like electrons, but with a positive charge, so when positrons and electrons meet and collide they alienate and release gamma rays and very specific energies.

NARRATIONTonight, the winds unexpectedly drop.

Dr Graham PhillipsWell, we haven’t got up in vain this morning. The weather is exceptionally calm and they’re going to have a crack at getting this balloon up.

NARRATIONThe gamma ray telescope will be launched. Work is frantic. There are many last-minute preparations. And it’s nerve-racking. All this prep might be in vain, because the tiniest of wind changes can terminate proceedings. But the odds of launch are good for now.

Eric BellmSeems like it might be 50-50, which is definitely an improvement on what we’ve been seeing in the past. Winds are pretty low today.

NARRATIONThe telescope is taken out to its launch spot on the runway. To check the winds, small helium balloons are released.

Weather GuyIt’s perfectly balanced there.

NARRATIONThe means it will ascend at precisely 600 feet per minute.

Dr Graham PhillipsHanging off the bottom there is the ballast. Now it’s just a couple of boxes of sand but that can be released remotely, when the balloon is up at 40 kilometres, to help control the height to some extent.

NARRATIONNow there’s a very nervous wait 'til day time, because the winds can change dramatically at this time. The weather balloon is tracked, giving very precise measurements of the lower level winds. They’re still light, so balloon rollout gets the go-ahead.

Dr Graham PhillipsThe balloon is made out of really thin plastic like lunch wrap, so they have to be very careful laying it out so it doesn’t tear.

NARRATIONThe protective orange sheath is stripped, and the balloon attached to the telescope. More weather checking and then the exciting news.

Bill SteppWell the winds have increased slightly, but they’re still within a manageable range. So we’re going to go ahead and launch.

Eric BellmWhen they fill it, they only fill a third when they are down on the ground, because it will expand as it goes up to altitude where there is lower pressure.

Dr Graham PhillipsThe balloon will take about 45 minutes to fully inflate. It takes three truckloads of helium.

NARRATIONThe balloon is meant to be released when it’s risen to the vertical position. But they seem to be having trouble. The onlookers have only seconds to run for their lives.

Dr Graham PhillipsAs you can see, there’s been some sort of disaster. It’s crashed basically, and taken cars out with it. We’ll find out what happened.

Eric BellmInstead of coming off the launch pad smoothly, and lifting straight off, we were stuck on there, so it looks like it caught badly and fell so they had to terminate.

NARRATIONThe official NASA inquiry into what went wrong is still ongoing.